Invasive Pest Research Articles

Identifying key monitoring areas for tree insect pest risks in China under climate change.

Climate change can exacerbate pest population growth, posing significant threats to ecosystem functions and services, social development, and food security. Risk assessment is a valuable tool for effective pest management that identifies potential pest expansion and ecosystem dispersal patterns. We applied a habitat suitability model coupled with priority protection planning software to determine key monitoring areas (KMA) for tree insect pest risks under climate change and used forest ecoregions and nature reserves to assess the ecological risk of insect pest invasion. Finally, we collated the prevention and control measures for reducing future pest invasions. The KMA for tree insect pests in our current and future climate is mainly concentrated in eastern and southern China. However, with climate change, the KMA gradually expands from southeastern to northeastern China. In the current and future climate scenarios, ecoregions requiring high monitoring levels were restricted to the eastern and southern coastal areas of China, and nature reserves requiring the highest monitoring levels were mainly distributed in southeastern China. Tree insect pest invasion assessment using ecoregions and nature reserves identified that future climates increase the risk of pest invasions in forest ecoregions and nature reserves, especially in northeastern China. The increased risk and severity of tree insect pest invasions require implementing monitoring and preventative measures in these areas. We effectively assessed the pest invasion risks using forest ecoregions and nature reserves under climate change. Our assessments suggest that monitoring and early prevention should focus on southeastern and northeastern China.

Response of hibiscus mealybug (Hemiptera: Pseudococcidae) to citrus volatiles induced by mechanical injury.

Hibiscus mealybug, Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae), is a recent invasive pest of citrus and many other crops in Florida. Nipaecoccus viridis attacks all above ground parts of citrus trees and heavy infestation can cause leaf drop and premature abortion of developing fruits. We quantified greater captures of N. viridis in cardboard band traps on areas of citrus trees that were intentionally injured by mechanical rasping of epidermal tissues as compared with similar but uninjured citrus branches. Direct field collection of headspace volatiles from mechanically injured or intact citrus branches revealed both qualitative and quantitative differences. Certain volatiles (γ-terpinene, citronellal, citronellyl acetate, β-E-farnesene, α-humulene, and α-E-E-farnesene) were only present in samples from damaged citrus branches. Behavioral assays using a laboratory Y-tube olfactometer revealed attraction of N. viridis to volatiles associated with mechanical damage of citrus including synthetic β-ocimene, γ-terpinene, sabinene, isomers of farnesene, and citronellal when loaded into lures at either of 2 concentrations (0.01 or 0.1 µg/µl). Subsequent field trapping experiments confirmed increased captures of various life stages of N. viridis in cardboard band traps baited with a 10.0 µg/µl concentration of farnesene:ocimene:sabinene blend (in 7:13:17 ratio), as well as those releasing either farnesene or ocimene alone at this same concentration, as compared with the mineral oil (diluent) negative control. Our results indicate that common plant related terpenes released by citrus following mechanical damage may be useful for development of an effective monitoring trap for N. viridis.

Assessing native parasitoids of the invasive pest Drosophila suzukii (Diptera: Drosophilidae) in the Southeastern USA.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), commonly known as spotted-wing Drosophila (SWD), is an invasive insect pest threatening the economy of many small fruit farms in the Americas and Europe. Biological control using parasitoids is a promising strategy for improving the sustainable management of SWD. To use the parasitoids as biocontrol agents, recognizing and understanding the presence and preference of North American native parasitoids and their local adaptation is necessary. We conducted 2 season-long field explorations of North American native parasitoids of SWD during 2021 and 2022 at major blueberry-producing locations in southeast GA, USA. A total of 371 parasitoids of Drosophila were collected using fruit-baited sentinel traps and classified into 3 families: Figitidae, Pteromalidae, and Diapriidae. Leptopilina boulardi (Hymenoptera: Figitidae) and Pachycrepoideus vindemmiae (Hymenoptera: Pteromalidae) were the most abundant species. The abundance of parasitoids was higher during the peak blueberry ripening period through the end of the harvest season compared to all other phenological stages. Out of the North American native parasitoids of SWD that we collected, Pachycrepoideus vindemmiae successfully parasitized SWD in its natural habitat, and L. boulardi only parasitized SWD larvae at a low rate of 7% in the laboratory, but it failed to emerge from all the parasitized SWD. Ultimately, we found that the existing North American native parasitoids were inadequate to suppress the SWD in these locations. Planned intervention with the classical release of Asian native specialist parasitoids in addition to the existing SWD management approaches was deemed necessary in these areas.

Isolation and identification of native Chilean entomopathogenic fungi and their potential for the control of Drosophila suzukii

Drosophila suzukii is an invasive pest of berries and other soft-skinned fruits, was first detected in Chile in 2017, and has since spread over 2,800 km from north to south. Sustainable control of the spotted-wing drosophila (SWD) is essential due the negative attitude of the consumers toward the excessive use of insecticides. During a survey in Chile for biological control agents, thirty-two isolates of entomopathogenic fungi (EPF) were isolated from mycotized insects and soil samples, identified through sequence analysis, and tested against D. suzukii adults under laboratory conditions. The EPF identified are Akanthomyces muscarius, Beauveria bassiana, Beauveria pseudobassiana, Clonostachys rosea, Metarhizium alvesii, Metarhizium brunneum and Metarhizium robertsii. Six isolates caused 100 % of mortality of D. suzukii adults within ten days after the initial exposition to conidia; these included four B. bassiana isolates (LSB 110, LSB 114, LSB 122 and LSB 125), one M. robertsii isolate (LSB 115) and one M. brunneum isolate (LSB 127). LSB 122 and LSB 125 induced the shortest lethal time (LT50 4 and 4.2 days, respectively), while Akanthomyces and Clonostachys caused ≤36 % cumulative mortality of the adults at 10 days of exposure. These results indicate that isolates of B. bassiana, M. robertsii and M. brunneum have significant potential as microbial control agents against D. suzukii adults. This study marks a critical step forward in identifying and validating native entomopathogenic fungi in Chile for sustainable pest management. Future work will focus on further testing these isolates under laboratory, semi-field and field conditions to optimize their application in real-world agricultural settings.

The hindgut microbiota of coconut rhinoceros beetles (Oryctes rhinoceros) in relation to their geographical populations.

The coconut rhinoceros beetle (CRB, Oryctes rhinoceros) is a palm tree pest capable of rapidly expanding its population in new territories. Previous studies identified a digestive symbiosis between CRB and its gut microbes. However, no research compared the genetic variation of CRBs with their hindgut microbiota on a global scale. This study aims to investigate the genetic divergence of CRB and the compositional variation of CRB's microbiota across different geographical locations, and explore the association between them and their predicted functional profiles and environmental data. The research reveals a distinct and consistent microbial community within local populations, but it varies across different geographical populations. The microbial functional profiles linked to the production of digestive enzymes, including cellulases and ligninases, are nonetheless globally conserved. This suggests that CRBs employ specific mechanisms to select and maintain microbes with functional benefits, contributing to host adaptability, stress tolerance, and fitness. The CRB microbial communities did not appear to recapitulate the genetic variation of their hosts. Rather than depend on obligate symbionts, CRBs seem to establish similar digestive associations with whatever environmentally acquired microbes are available wherever they are, aiding them in successfully establishing after invading a new location.IMPORTANCECoconut rhinoceros beetles (CRBs) are notorious pests on Arecaceae plants, posing destructive threats to countries highly reliant on coconut, oil palm, and date palm as economic crops. In the last century, CRBs have rapidly expanded their presence to territories that were once free of these beetles. The United States, for instance, has officially designated CRBs as invasive and alien pests. Given their remarkable ability to swiftly adapt to new environments, their gut microbes may play a crucial role in this process. While the microbiota of CRBs vary depending on geographical location, these beetles consistently exhibit a functionally identical digestive association with locally acquired microbes. This underscores the significance of CRB-microbe association in shaping the adaptive strategies of this agricultural pest.

Prediction of number of generations of serpentine leaf miner, <i>Liriomyza trifolii</i> (Burgess) (Agromyzidae: Diptera) in India assessed by CLIMEX under climate change scenario

The serpentine leaf miner, Liriomyza trifolii, is an invasive pest that affects plants, causing damage to the leaves and reducing crop yield. Number of generations of serpentine leaf miner was assessed under current and expected future climate change scenarios. The assessment was done for Representative Concentration Pathway (RCP 8.5) future climate change scenario in India. L. trifolii would have had 16-19 generations, in base line and 17-24 in 2050-time frame under future climate change in Andhra Pradesh conditions. Under Arunachal Pradesh conditions, it would have had 6-14 generations in base line and is expected to complete the same number of generations in 2050, scenario. Under Sikkim conditions 3 - 4 and 5 number of generations were assessed for present and future climate change scenario. Suitability of the localities was expressed in terms of Ecoclimatic index (EI) ranging from 0 to > 20 by combining the interaction effect of various stress indices and growth indices for the development of L. trifolii. It was observed that in temperate areas the pest incidence may increase in future, in contrast to the decreasing trend in areas where already the prevailing temperatures are near upper thresholds. It is therefore expected that number of generations of L. trifolii would increase with the rising temperatures under climate change situations.

Ionotropic Receptor 8a (Ir8a) Plays an Important Role in Acetic Acid Perception in the Oriental Fruit Fly, Bactrocera dorsalis.

Bactrocera dorsalis is one of the major invasive pests worldwide. The acetic acid-enriched sweet bait trapping is an important method for monitoring and controlling this fly. Several studies showed that acetic acid is perceived by ionotropic receptors (IRs). Thus, we annotated 65 IR genes in the B. dorsalis genome. We also investigated the IRs involved in acetic acid perception in this fly by behavioral, electrophysiological, and molecular methods. As the results indicated, the antennae are the main olfactory organs to sense acetic acid. Among the antennal IRs showed acetic acid-induced expression profiles, IR8a was proven to perceive acetic acid by CRISPR/Cas9-mediated mutagenesis. Additionally, calcium imaging showed that IR64a and IR75a are potential acetic acid receptors respectively co-expressed with IR76b and IR8a. This study represents the first comprehensive characterization of IRs in B. dorsalis at the whole-genome level, revealing the significant role of IRs in acetic acid perception.

Characterization of a gene conferring resistance to US Russian wheat aphid biotypes in the Iranian wheat landrace PI 625139

AbstractRussian wheat aphid (RWA, Diuraphis noxia Kurdjumov) is a highly invasive and destructive wheat pest evolving rapidly to overcome host resistance. Novel genes conferring resistance to multiple RWA biotypes are needed to sustain wheat production. The Iranian landrace PI 625139 is resistant to all five US RWA biotypes. To map the RWA resistance gene in PI 625139, both F2 and F2:3 populations were developed from cross PI 625139 × Smith's Gold, and the F2:3 population was evaluated for responses to five RWA biotypes, RWA1, RWA2, RWA3/7, RWA6, and RWA8. RWA assays identified a single gene in PI 625139, designated Dn625139, conditioning resistance to all five US RWA biotypes. Selective genotyping of a subset of F2 plants using genotyping‐by‐sequencing (GBS) revealed a set of single‐nucleotide polymorphism (SNP) markers on the short arm of chromosome 7D that are closely associated with RWA resistance. Kompetitive allele‐specific PCR (KASP) markers were developed from selected GBS‐SNPs in 7DS. Genetic analysis using the new KASP and simple sequence repeat (SSR) markers placed Dn625139 to a 2.6 cM interval. Dn625139 was 1.2 cM proximal to the KASP marker Stars‐KASP1007 (169.57 Mb) and 1.4 cM distal to the SSR marker Stars1039 (195.27 Mb) in the International Wheat Genome Sequencing Consortium (IWGSC) RefSeq v2.1 reference sequence, and co‐segregated with the SSR marker Stars1029 (180.82 Mb). Dn625139 is a valuable gene conferring resistance to multiple RWA biotypes, and the molecular markers developed in this study can facilitate its rapid introgression into locally adapted cultivars to enhance wheat RWA resistance.

Chromosome Structural Rearrangements in Invasive Haplodiploid Ambrosia Beetles Revealed by the Genomes of Euwallacea fornicatus (Eichhoff) and Euwallacea similis (Ferrari) (Coleoptera, Curculionidae, Scolytinae).

Bark and ambrosia beetles are among the most ecologically and economically damaging introduced plant pests worldwide. Life history traits including polyphagy, haplodiploidy, inbreeding polygyny, and symbiosis with fungi contribute to their dispersal and impact. Species vary in their interactions with host trees, with many attacking stressed or recently dead trees, such as the globally distributed Euwallacea similis (Ferrari). Other species, like the Polyphagous Shot Hole Borer Euwallacea fornicatus (Eichhoff), can attack over 680 host plants and is causing considerable economic damage in several countries. Despite their notoriety, publicly accessible genomic resources for Euwallacea Hopkins species are scarce, hampering our understanding of their invasive capabilities as well as modern control measures, surveillance, and management. Using a combination of long and short read sequencing platforms, we assembled and annotated high quality (BUSCO > 98% complete) pseudo-chromosome-level genomes for these species. Comparative macrosynteny analysis identified an increased number of pseudo-chromosome scaffolds in the haplodiploid inbreeding species of Euwallacea compared to diploid outbred species, due to fission events. This suggests that life history traits can impact chromosome structure. Further, the genome of E. fornicatus had a higher relative proportion of repetitive elements, up to 17% more, than E. similis. Metagenomic assembly pipelines identified microbiota associated with both species including Fusarium fungal symbionts and a novel Wolbachia strain. These novel genomes of haplodiploid inbreeding species will contribute to the understanding of how life history traits are related to their evolution and to the management of these invasive pests.

Vibro-Acoustic Signatures of Various Insects in Stored Products.

Stored products, such as grains and processed foods, are susceptible to infestation by various insects. The early detection of insects in the supply chain is crucial, as introducing invasive pests to new environments may cause disproportionate harm. The STAR Center at Stevens Institute of Technology developed the Acoustic Stored Product Insect Detection System (A-SPIDS) to detect pests in stored products. The system, which comprises a sound-insulated container for product samples with a built-in internal array of piezoelectric sensors and additional electret microphones to record outside noise, was used to conduct numerous measurements of the vibroacoustic signatures of various insects, including the Callosobruchus maculatus, Tribolium confusum, and Tenebrio molitor, in different materials. A normalization method was implemented using the ambient noise of the sensors as a reference, to accommodate for the proprietary, non-calibrated sensors and allowing to set relative detection thresholds for unknown sensitivities. The normalized envelope of the filtered signals was used to characterize and compare the insect signals by estimating the Normalized Signal Pulse Amplitude (NSPA) and the Normalized Spectral Energy Level (NSEL). These parameters characterize the insect detection Signal Noise Ratio (SNR) for pulse-based detection (NSPA) and averaged energy-based detection (NSEL). These metrics provided an initial step towards the design of a reliable detection algorithm. In the conducted tests NSPA was significantly larger than NSEL. The NSPA reached 70 dB for T. molitor in corn flakes. The insect signals were lower in flour where the averaged NSPA and NSEL values were around 40 dB and 11 dB to 16 dB, respectively.

Identification of Multifunctional Putative Bioactive Peptides in the Insect Model Red Palm Weevil (Rhynchophorus ferrugineus)

Innate immunity, the body’s initial defense against bacteria, fungi, and viruses, heavily depends on antimicrobial peptides (AMPs), which are small molecules produced by all living organisms. Insects, with their vast biodiversity, are one of the most abundant and innovative sources of AMPs. In this study, AMPs from the red palm weevil (RPW) Rhynchophorus ferrugineus (Coleoptera: Curculionidae), a known invasive pest of palm species, were examined. The AMPs were identified in the transcriptomes from different body parts of male and female adults, under different experimental conditions, including specimens collected from the field and those reared in the laboratory. The RPW transcriptomes were examined to predict antimicrobial activity, and all sequences putatively encoding AMPs were analyzed using several machine learning algorithms available in the CAMPR3 database. Additionally, anticancer, antiviral, and antifungal activity of the peptides were predicted using iACP, AVPpred, and Antifp server tools, respectively. Physicochemical parameters were assessed using the Antimicrobial Peptide Database Calculator and Predictor. From these analyses, 198 putatively active peptides were identified, which can be tested in future studies to validate the in silico predictions. Genome-wide analysis revealed that several AMPs have predominantly emerged through gene duplication. Noticeably, we detect a newly originated defensin allele from an ancestral defensin via the deletion of two amino acids following gene duplication in RPW, which may confer an enhanced resilience to microbial infection. Our study shed light on AMP gene families and shows that high duplication and deletion rates are essential to achieve a diversity of antimicrobial mechanisms; hence, we propose the RPW AMPs as a model for exploring gene duplication and functional variations against microbial infection.

The use of visual and olfactory cues by adult Spodoptera frugiperda (Lepidoptera: Noctuidae) while foraging.

The fall armyworm Spodoptera frugiperda (J.E. Smith; Lepidoptera: Noctuidae) is a notorious invasive insect pest. It is very important to understand the foraging behavior of this pest to develop more effective lures to monitor the immigration of this pest. In this study, the use of visual and olfactory cues in the foraging behavior of S. frugiperda was investigated through an attraction experiment in which color (produced from 8 different colored artificial flowers), odor (produced from honey water), and odorous color (produced from artificial flowers supplemented with honey water) were used. When we used 8 different colors to elicit adult responses, S. frugiperda showed a significant color preference despite limited activity (i.e., the total number of visits to the attractant), with black being the most preferred color, followed by orange preferred by both sexes and blue and green preferred only by females. When honey water was used as an attractant, S. frugiperda had relatively greater odor activity than color activity. When we sprayed the artificial flowers with honey, S. frugiperda showed even greater activity in terms of odor color than in terms of color or odor. Compared with male S. frugiperda, female adult S. frugiperda presented greater activity in response to all types of attractants. These findings suggest that S. frugiperda adults rely primarily on olfaction for foraging, with vision as a secondary sense, and that the combined use of olfactory and visual cues increases foraging efficiency. These results provide reference data for designing trapping strategies to monitor and control S. frugiperda.

Early Detection of Dendroctonus valens Infestation with UAV-Based Thermal and Hyperspectral Images

Dendroctonus valens is one of the main invasive pests in China, causing serious economic and ecological damage. Early detection and control of D. valens can help prevent further outbreaks. Based on unmanned aerial vehicle (UAV) thermal infrared and hyperspectral data, we compared the spectral characteristics of Pinus sylvestris var. mongolica in three states (healthy, early-infested, and dead), and constructed a classification model based on the random forest algorithm using four spectral datasets (reflectance, first derivative, second derivative, and spectral vegetation index) and one temperature parameter dataset. Our results indicated that the spectral differences between healthy and early-infested trees mainly occur in the near-infrared region, with dead trees showing different characteristics. While it was effective to distinguish healthy from early-infested trees using spectral data alone, the addition of a temperature parameter further improved classification accuracy across all datasets. The combination of the spectral vegetation index and temperature parameter achieved the highest accuracy at 93.75%, which is 3.13% higher than using the spectral vegetation index alone. This combination also significantly improved early detection precision by 13.89%. Our findings demonstrated the applicability of UAV-based thermal infrared and combined hyperspectral datasets in monitoring D. valens early-infested trees, providing important technical support for the scientific prevention and control of D. valens.

Image segmentation for pest detection of crop leaves by improvement of regional convolutional neural network

Pest detection is important for crop cultivation. Crop leaf is the main place of pest invasion. Current technologies to detect crop pests have constraints, such as low efficiency, storage demands and limited precision. Image segmentation is a fast and efficient computer-aided detection technology. High resolution image capture solidly supports the crucial processes in discerning pests from images. Study of analytical methods help parse information in the images. In this paper, a regional convolutional neural network (R-CNN) architecture is designed in combination with the radial bisymmetric divergence (RBD) method for enhancing the efficiency of image segmentation. As a special application of RBD, the hierarchical mask (HM) is produced to endorse detection and classification of the leaf-dwelling pests, offering enhanced efficiency and reduced storage requirements. Moreover, to deal with some mislabeled data, a threshold variable is introduced to adjust a fault-tolerant mechanism into HM, to generate a novel threshold-based hierarchical mask (TbHM). Consequently, the hierarchical mask R-CNN (HM-R-CNN) model and the threshold-based hierarchical mask R-CNN (TbHM-R-CNN) model are established to detect various types of healthy and pest-invasive crop leaves to select the regional image features that are rich in pest information. Then simple linear iterative clustering (SLIC) method is incorporation to finish the image segmentation for the classification of pest invasion. The models are tuned and optimized, then validated. The most optimized modeling results are from the TbHM-R-CNN model, with the classification accuracy of 96.2%, the recall of 97.5% and the F1 score of 0.982. Additionally, the HM-R-CNN model observed appreciable results second only to the best model. These results indicate that the proposed methodologies are well-suited for training and testing a dataset of plant diseases, offering heightened accuracy in pest classification. This study revealed that the proposed methods significantly outperform the existing techniques, marking a substantial improvement over current methods.

Role of Gut Bacteria in Enhancing Host Adaptation of Tuta absoluta to Different Host Plants.

The insect gut bacteria play important roles in insect development and growth, such as immune defense, nutrient metabolism, regulating insect adaptations for plants, etc. The Tuta absoluta (Meyrick) is a destructive invasive pest that mainly feeds on solanaceae plants. However, the relationship between gut microflora and host adaption of T. absoluta remains to be known. In this study, we first compared the survival adaptability of T. absoluta feeding with two host plants (tomatoes and potatoes). The T. absoluta completed the generation cycle by feeding on the leaves of both plants. However, the larvae feeding on tomato leaves have shorter larvae durations, longer adult durations, and a greater number of egg production per female. After Single Molecular Real-Time (SMRT) sequencing, according to the LDA Effect Size (LEfSe) analysis, the gut bacterial biomarker of T. absoluta fed on tomato was Enterobacter cloacae and the gut bacterial biomarker of T. absoluta fed on potatoes was Staphylococcus gallinarum and Enterococcus gallinarum. Furthermore, a total of 6 and 7 culturable bacteria were isolated from the guts of tomato- and potato-treated T. absoluta, respectively. However, the isolated strains included bacterial biomarkers E. cloacae and S. gallinarum but not E. gallinarum. In addition, different stains bacterial biomarkers on T. absoluta feeding selection were also studied. E. cloacae enhanced the host preference of the SLTA (T. absoluta of tomato strain) for tomato but had no impact on STTA (T. absoluta of potato strain). S. gallinarum improved the host preference of STTA to a potato but did not affect SLTA. The results showed that the gut bacteria of T. absoluta were affected by exposure to different host plants, and the bacterial biomarkers played an important role in host adaptability. This study not only deepens our understanding of gut bacteria-mediated insect-plant interactions but also provides theoretical support for the development of environmentally friendly and effective agricultural pest control methods.

Multi-omics analysis reveal the fall armyworm Spodoptera frugiperda tolerate high temperature by mediating chitin-related genes

Climate change facilitates the rapid invasion of agricultural pests, threatening global food security. The fall armyworm Spodoptera frugiperda is a highly polyphagous migratory pest tolerant to high temperatures, allowing its proliferation in harsh thermal environments. We aimed to demonstrate mechanisms of its high-temperature tolerance, particularly transcriptional and metabolic regulation, which are poorly understood. To achieve the aim, we examined the impact and mechanism of heat events on S. frugiperda by using multiple approaches: ecological measurements, transcriptomics, metabolomics, RNAi, and CRISPR/Cas9 technology. We observed that several physiological indices (larval survival rate, larval period, pupation rate, pupal weight, eclosion rate, and average fecundity) decreased as the temperature increased, with the 32 °C treatment displaying a significant difference from the control group at 26 °C. Significantly upregulated expression of genes encoding endochitinase and chitin deacetylase was observed in the chitin-binding, extracellular region, and carbohydrate metabolic process GO terms of hemolymph, fat body, and brain, exhibiting a tissue-specific pattern. Significantly enriched pathways (e.g., cutin, suberin, and wax biosynthesis; oxidative phosphorylation and cofactor biosynthesis; diverse amino acid biosynthesis and degradation; carbon metabolism; and energy metabolism), all of which are essential for S. frugiperda larvae to tolerate temperature, were found in metabolites that were expressed differently. Successful RNA interference targeting of the three chitin-related genes reduced gene expression levels and larval survival rate. Knockout of the endochitinase gene by using the CRISPR/Cas9 system significantly reduced the relative gene expression and increased sensitivity to high-temperature exposure. On the basis of our findings, theoretical foundations for understanding the high-temperature tolerance of S. frugiperda populations and latent genetic control strategies were established.

Impact of Aggregation Pheromone Traps on Spatial Distribution of Halyomorpha halys Damage in Apple Orchards.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive pest causing significant damage to tree crops. Our study examined the impact of newly designed aggregation pheromone-baited 'mini-sailboat' (MSB) traps for controlling H. halys and its effect on the spatial distribution of fruit damage. Four replicates of four traps, with a total of 16 MSB traps, were placed along a 1.3 km border of apple orchards, concentrating the traps on one side of the orchards. A fruit damage assessment for incidence and severity was conducted at increasing distances from the orchard border where the traps were placed, encompassing 107 assessment points. Our study showed that deploying MSB traps along the orchard border significantly increased fruit damage within the first 45 m compared to control plots without traps. However, beyond the first 45 m from the border, there was a significant reduction in damage incidence. In the treated plots, 50% of the damage occurred within 26 m of the traps, while in control plots, within 85 m. Shifting the fruit damage pattern means restricting the pests lingering in a narrow strip near the MSB traps, which paves the way for improved techniques to restructure the crop perimeter.

Marking Helicoverpa zea (Lepidoptera: Noctuidae) with fluorophores for use in mark-release-recapture research

Abstract Knowledge of insect dispersal and long-distance migratory flight capacity and patterns represent key factors needed for risk assessment of invasive pest species, insecticide resistance management, and more effective pest control. Having operative tools to both mark and track insect pest movement is therefore critical to achieving such goals. Here, we describe a new procedure for marking Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), one of the most economically important crop pests in the United States. Adult H. zea moths were effectively marked using the liquid fluorophore cartax green, a persistent UV-fluorescent pigment, both directly by topical application and indirectly by briefly submerging pupae in the marking solution prior to adult emergence. Regardless of the application method, the cartax mark was retained on the moths throughout their entire adult lifespan. No mortality differences were observed between cartax green-marked and water-marked (control) moths. Additionally, using rotary flight mills, we found no significant differences in several flight parameters, including total number of flights, flight speeds, flight distances, or flight durations between unmarked and cartax-marked moths. Under laboratory conditions, we did observe the lateral transfer of different colored fluorophores between moths, indicating that undesirable marking could potentially occur. Moreover, we found that not all fluorophores were equally retained on H. zea moths, with cartax green remaining intact on moths longer than did a corresponding magenta fluorophore. The results show that cartax green fluorophore could be a practical marker for H. zea and other holometabolous species targeted for large-scale mark-release-recapture research.

Climate change impacts on worldwide ecological niche and invasive potential of Sternochetus mangiferae.

Present climate studies on invasive species imply that climate change will alter the habitat suitability of invasive pests, especially given the projected rise in average global temperatures by the end of 2100. However, globally, limited information exists on the habitat suitability of the mango stone weevil, Sternochetus mangiferae Fabricius, which impedes the development of early detection and preventive measures. Herein, we used the MaxEnt model to estimate the potential global geographical distribution of S. mangiferae. Our results revealed that thermal conditions played a significant role in explaining the invasion risk of S. mangiferae. Habitat suitability was found in all continents, except Antarctica. Under the present condition, habitat suitability covered 5.67 × 107 km2. For ssp126, habitat suitability will decrease from the 2060s (5.58 × 107 km2) and 2080s (5.57 × 107 km2). Similarly, under ssp585, suitable areas will decrease from 5.62 × 107 to 5.51 × 107 km2 for the 2060s and 2080s, respectively. Our study has estimatedvariability in the habitat suitability of S. mangiferae which establishes a foundation for determining global riskassessment and response plans for the pest. This study also identifies areas where the pest is inherently more vulnerable to the impacts of changing climates and enables forecasting of its potential distribution in a dynamic world. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

First Report of Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae) in Oklahoma.

The corn leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), is an invasive insect that can cause damage to maize (Zea mays L.) in two ways: by direct feeding and the transmission of several plant pathogens. Dalbulus maidis is an invasive and serious economic pest of maize that has spread from its center of origin in Mexico to the southernmost parts of the United States. Prior to 2024, corn leafhoppers had not been documented in Oklahoma, and their spread northward toward the United States corn belt is of significant concern. Here, we provide the first reports of the insect in maize in several Oklahoma counties. Insect specimens were collected at various commercial and experimental field sites by Oklahoma State University research and extension personnel. The identity of the insect species was validated through morphological and molecular taxonomy. The presence records for the corn leafhopper presented here provide valuable information for future monitoring and management efforts of this economically important pest and disease.